高稳定性荧光碳点油墨的制备及其防伪性能研究

Preparation of highly stable fluorescent carbon dots ink and its anti-counterfeiting performance

以柠檬酸、尿素和丙烯酰胺为前驱体,制备了具有高稳定性的氮掺杂荧光碳点油墨应用于防伪包装。首先以柠檬酸、尿素为前驱体,采用水热法在180℃条件下反应6h,制备氮掺杂碳点(记作NCDs-1);然后以柠檬酸、尿素和丙烯酰胺为前驱体制备氮掺杂碳点(记作NCDs-2);将NCDs-1、NCDs-2分散在水中制备了氮掺杂荧光碳点油墨。通过透射电子显微镜、扫描电子显微镜、X射线衍射仪、傅里叶变换红外光谱仪、X射线光电子能谱仪、荧光光谱仪等对样品的形貌、结构和表面元素组成、荧光性能进行了表征并考察了不同环境下油墨的稳定性。结果表明:NCDs-2粒径分布在2~9nm之间,在水中分散均匀;氮掺杂碳点的最佳激发波长为370nm,最佳发射峰位置在450nm;在无荧光背景的纤维素纸基上油墨表现出良好的稳定性,且在紫外光照射下发出明亮的蓝色荧光;以柠檬酸、尿素、丙烯酰胺为前驱体制备的氮掺杂荧光碳点油墨稳定性良好,可用于香烟盒的防伪包装。

A highly stable nitrogen-doped carbon dots(NCDs)fluorescent ink for anti-counterfeiting packaging was prepared using citric acid,urea and acrylamide as precursors.Firstly,nitrogen-doped carbon dots(NCDs-1)were prepared by hydrothermal method at 180℃for 6h with citric acid and urea as precursors.Subsequently,nitrogen-doped carbon dots(NCDs-2)were prepared with citric acid,urea and acrylamide as precursors.Finally,nitrogen-doped carbon dots fluorescent ink was prepared by dispersing NCDs-1 and NCDs-2 in water.The morphology,structure,surface element composition and fluorescence properties of the samples were characterized by transmission electron microscope,scanning electron microscope,X-ray diffractometer,Fourier transform infrared spectrometer,X-ray photoelectron spectrometer and fluorescence spectrometer,and the stability of the ink under different environments was investigated.The results showed that the particle size of NCDs-2 was between 2~9nm,and these particles were dispersed evenly in water.In addition,the best excitation wavelength of NCDs was 370nm,and the best emission peak was 450nm.The inks exhibited good stability on cellulose paper base without fluorescent background,and emitted bright blue fluorescence under UV light.The NCDs fluorescent ink prepared with citric acid,urea and acrylamide as precursors had good stability and could be used for anti-counterfeiting packaging on cigarette boxes.